Methods and Apparatuses for Encoding and Decoding Object-Based Audio Signals

1. A method of decoding an audio signal, comprising: receiving a downmix signal and object-based side information, the downmix signal being obtained by downmixing one or more object signal; receiving control information, the control information controlling for position or level of the object signal being included in the downmix signal; extracting metadata indicating description of object signal from the object-based side information; generating a preprocessing information for modifying the downmix signal based on the object-based side information and the control information; generating channel-based side information based on the object-based side information and the control information; modifying the downmix signal by applying the preprocessing information to the downmix signal; and generating a multi-channel audio signal by using the modified downmix signal and the channel-based side information, wherein the metadata uses text format.

2. The audio decoding method of claim 1 , wherein the metadata comprises at least one of a number corresponding to the object signal and a description of the object signal.

3. An audio decoding apparatus, comprising: a demultiplexer configured to extract a downmix signal, object-based side information and control information from an input audio signal, the downmix signal being obtained by downmixing one or more object signal and the control information controlling for position or level of the object signal being included in the downmix signal; a parameter converter configured to extract metadata indicating description of object signal from a header of the object-based side information and generate a preprocessing information for modifying the downmix signal based on the object-based side information and the control information and generate channel-based side information based on the object-based side information and the control information; a preprocessor configured to modify the downmix signal by applying the preprocessing information to the downmix signal; and a multi-channel decoder configured to a multi-channel audio signal by using the modified downmix signal and the channel-based side information, wherein the metadata uses text format.

4. The apparatus of claim 3 , wherein the metadata comprises at least one of a number corresponding to the object signal and a description of the object signal.